200 hard miles on some hot roads and some occasional traffic, idling much much better now. I will vent lower later if it gets messy.
Thanks for all the great help!
This has been quite frustrating for a couple years.

 

What sensors do you think are being affected? The only exposed sensor in the TB is the IAT sensor which I doubt is causing your issue. Other responses seem to imply that there is a mass airflow sensor which does not exist in the HD world. Yes, it's good to get the blowby out of the TB , but I think your issue lies elsewhere. Have you made sure the butterfly shaft is not cracked/ broken?

 

Check the battery after a full 24-hour charge and remove for a load test. Usually, kickbacks are caused by low amps and worn out battery. Low rpm would mean low voltage for electronics.

Do not spray any cleaner in there. No matter what it is, if it's strong enough to dissolve crud, it will wash it up past the o-ring in the servo control motor and then when dries, it makes matter worst. It does the same for throttle position sensor.

Shine a light down that IAC passage way and you will see it's huge. Just a touch on the pintle valve and a spray on a cotton cloth to wipe area around the butterfly and where it sits.

With the air filter off, he on and off will tell you the IAC is ok. It will close at key off, key on will jump it out and position for last idle. All it is is additional air besides the butterfly lock setting when the throttle is shut. That butterfly is a factory set with a flow meter.

If opening the throttle fixes it, it could be you got some bad gas with some moisture in it. However, ethanol gas usually fixes that in about 3-4 tanks full.

Idle circuit is very sensitive . Never have figured out why but starting in gear with mine cause it to jump like most any Harley and it will confuse idle but mine will be 200 or so too high for a few miles of stops or a off/on restart

 

Idle Air Control Valve is getting the blame. Sits on top of the throttle body.

 

The kickback stopped when I cleaned the IACV with the wrong spray.
I'm thinking I should just replace the IACV since I have abused it.
Not understanding what the ethanol gas fixes? Gas comes in after the IACV?

 

Kick back is a sure sign quite often of a weak battery down in amp and not strong enough to power thru that first crank that cleans out vapors in the cylinder that tend to explode at the wrong time in the hot motor starting up.

If you read my post above, I was referring to maybe you got a little water in a tank of gas. So called Gas Dry in a bottle is nothing but straight ethanol. 10% ethanol gas will do the same thing. Just takes a while since it cannot absorb but so much

Do the battery. You will know if you hurt the IAC in a week or so. Any spray is wrong for it.

Nothing but a little-filtered air goes thru the IAC valve. It's just a passage around the butterfly that the ECM opens up to allow enough air to maintain 1000 or so idle rpm.